On Sunday, 26 September 2021 11:57:43 BST Peter Humphrey wrote:
> Hello list,
>
> I have an external USB-3 drive with various system backups. There are 350
> .tar files (not .tar.gz etc.), amounting to 2.5TB. I was sure I wouldn't
> need to compress them, so I didn't, but now I think I'm going to have to.
> Is there a reasonably efficient way to do this? I have 500GB spare space on
> /dev/sda, and the machine runs constantly.
To complete the topic, and in case anyone's interested, I've settled on the
following method, which could have been made more general, but this way I
have a complete set of compressed tarballs in two places in case I need to
recover something.
This is the command to compress one week's backups:
# (cd /mnt/sdc/wstn/main/vvv.old && time (for tar_archive in *.tar; do zstd -
T0 --rm "${tar_archive}" -o /mnt/bu-space/vvv.old/"${tar_archive}.zst"; done
&& cp /mnt/bu-space/vvv.old/* /mnt/sdc/wstn/main/vvv.old/ && sync))
This was 36GB and took 20 minutes.
--
Regards,
Peter.
